Processing – morphology – property relationships of polyamide 6/polyethylene blend–clay nanocomposites

Abstract

Abstract. In this work, we studied the effect of the method of preparation and of reprocessing on the morphology and, consequently, on the physical properties of polyamide 6 (PA6)/ high density polyethylene (HDPE)-clay nanocomposite blends in the presence of different compatibilizers. In particular, the nanocomposites were obtained by melt mixing using a corotating twin screw extruder (E1). The blends thus obtained were re-extruded (E2) under the same operating conditions. Moreover, blends with the same final composition were produced using a masterbatch of the compatibilizer with the clay prepared in a separated stage in a batch mixer (MB). All the materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD) analyses. In addition, the rheological behaviour and the, tensile and impact, properties were evaluated. The XRD and TEM analysis showed that re-extrusion slightly improves the morphology of the nanocomposites. A further improvement of the morphology, in terms of lower clay dimension and better dispersion, was observed in the MB blends. The results of the mechanical tests showed that reprocessing (E2) induced an increase of all the properties for all the three systems. A further general increase of the mechanical properties was showed by the MB blends.

The Effect of Multiple Extrusions on the Properties of Montmorillonite Filled Polypropylene

“…The supplementary stresses induced on the composite by multiple reprocessing allow yet a further dispersion of the MMT filler with consequently a higher intercalation level. This enhancement in interlayer distance by multiple processing has also been reported in other polymeric matrices by other authors; for example in a polyamide-polyethylene blend [32], poly (acrylonitrile-butadiene-styrene) [20] and polyamide [16].…”

Effect of migration of layered nanoparticles during melt blending on the phase morphology of poly (ethylene terephthalate)/polyamide 6/montmorillonite ternary nanocomposites

“…4(a). 26,27 At the same time, from Fig. 7(b) we can see that the varying trends in tensile strength of PET/ PA6 (30/70) nanocomposites are complicated.…”

Polyamide blend-based nanocomposites: A review

“…These concerns are related to possible degradation occurring during processing and reprocessing, particularly when multiple reprocessing cycles are performed [76]. Scaffaro et al [77] found that re-extrusion slightly improves the morphology of PA 6/PE blend-clay nanocomposites most likely due to the supplementary stresses induced on the blend in the second processing step, allowing further dispersion of the nanofiller with a consequently higher intercalation level.…”